High levels of estrogen in older women may be a significant risk factor for dementia, according to new research.

French Study

Researchers in France were interested in the effect of estrogen on dementia risk and conducted a study to determine whether there was any connection. The researchers analyzed data from a previous study including more than 5,600 postmenopausal women aged 65 and older. They measured the estrogen levels of the women who participated in the study and used this data to form the baseline of their research.

Four years after the initial data evaluation, the researchers compared the estrogen levels of 543 women without dementia and 132 women who had been diagnosed with dementia. They were surprised at what they found.

Estrogen and Dementia Risk 

The scientists accounted for external risk factors that could affect the risk, like diabetes, high blood pressure, and heart disease. They discovered that even after taking those into account, women with higher estrogen levels had more than twice the dementia risk than those with lower levels.

Diabetes only seemed to worsen the problem and increase the risk even more, according to the researchers. These findings have caused people to question the worthiness of hormone therapy and other hormone treatments.

“While it was long believed that estrogens — either endogenous or therapeutic — were good for women’s health, especially for the heart and brain, our study together with other current data challenge this dogma,” said Dr. Pierre-Yves Scarabin, director of research at the French National Institute of Health and Medical Research (INSERM), who led the study.

Moving Forward

It seems that the problem may lie only with women of senior age, because estrogen has been shown to have positive effects on the risk of dementia in middle aged women. The study didn’t prove a cause and effect relationship, though, so the researchers involved have made it clear that this isn’t a push for any one to stop their hormone treatment.

“Before we make recommendations, we need to do clinical trials,” said Dr. Sam Gandy, director of the Center for Cognitive Health at the Mount Sinai Hospital in New York City.

The risk of dementia is something that researchers are putting a lot of effort into, as the number of people with dementia continues to increase and is expected to triple by 2050. Read more about how to reduce your risk of dementia here.